I have two questions about using GSAS within this environment.
First of all, I tried to do a refinement of silicon X-ray diffraction data to
obtain the zero point for our diffractometer. For now, I have been running the
FULL GSAS option in InsightII and typing commands at the GSAS command line.
The profile that is calculated for silicon is wrong. The calculated profile
includes zero intensity for the (220) and (422) peaks, 100% intensity for the
(222) peak, and 16% intensity for the (333) peak. Obviously this does not
match the experimental data at all! I have checked all of the phase
information in the .exp file, and the file seems to include the correct space
group and atom positions for silicon. Has anyone seen this problem before?
Have I done something wrong? I am stumped.
The second question has to do with how to work on a refinement in InsightII,
stop, and then continue the refinement at a later point in time. I have not
been able to successfully setup a Rietveld refinement other than by setting it
up as NEW each time I begin. Any suggestions?
By the way, I have sent both of these questions to the Biosym techcenter, but
have not heard back from anyone yet, so I thought I would try here...
Thanks in advance for the help!
Margret J. Geselbracht
Assistant Professor of Chemistry
Reed College
Portland, OR 97202
margret.geselbracht@reed.edu